// ===== 文件：src/main/java/com/encoding/Config.java =====
package com.encoding;
 
import java.io.InputStream;
import java.util.Properties;
 
/**
 * 讀取 application.properties 配置。
 */
public class Config {
    private String defaultSrcCharset;
    private String defaultDestCharset;
    private int threadCount;
    private int bufferSize;
 
    public Config() {
        // 默認值
        defaultSrcCharset = "UTF-8";
        defaultDestCharset = "GBK";
        threadCount = Runtime.getRuntime().availableProcessors();
        bufferSize = 8192;
        // 加載外部配置
        try (InputStream in = getClass()
                .getClassLoader()
                .getResourceAsStream("application.properties")) {
            if (in != null) {
                Properties p = new Properties();
                p.load(in);
                defaultSrcCharset = p.getProperty(
                    "app.srcCharset", defaultSrcCharset);
                defaultDestCharset = p.getProperty(
                    "app.destCharset", defaultDestCharset);
                threadCount = Integer.parseInt(
                    p.getProperty("app.threadCount", String.valueOf(threadCount)));
                bufferSize = Integer.parseInt(
                    p.getProperty("app.bufferSize", String.valueOf(bufferSize)));
            }
        } catch (Exception e) {
            System.err.println("加載配置失敗，使用默認值");
        }
    }
 
    // getters...
    public String getDefaultSrcCharset() { return defaultSrcCharset; }
    public String getDefaultDestCharset() { return defaultDestCharset; }
    public int getThreadCount() { return threadCount; }
    public int getBufferSize() { return bufferSize; }
}
 
// ===== 文件：src/main/java/com/encoding/EncodingConverter.java =====
package com.encoding;
 
import java.io.*;
import java.nio.charset.Charset;
 
/**
 * 核心編碼轉換器：從 InputStream 讀取，使用 srcCharset 解碼，
 * 再用 destCharset 編碼寫入 OutputStream。
 */
public class EncodingConverter {
 
    /**
     * 將輸入流按 srcCharset 解碼，按 destCharset 編碼寫入輸出流。
     */
    public static void convert(
            InputStream in,
            Charset srcCharset,
            OutputStream out,
            Charset destCharset,
            int bufferSize) throws IOException {
        // Reader/Writer 橋接
        try (Reader reader = new BufferedReader(
                 new InputStreamReader(in, srcCharset), bufferSize);
             Writer writer = new BufferedWriter(
                 new OutputStreamWriter(out, destCharset), bufferSize)) {
            char[] buf = new char[bufferSize];
            int len;
            while ((len = reader.read(buf)) != -1) {
                writer.write(buf, 0, len);
            }
            writer.flush();
        }
    }
}
 
// ===== 文件：src/main/java/com/encoding/FileUtils.java =====
package com.encoding;
 
import java.io.IOException;
import java.nio.file.*;
import java.util.ArrayList;
import java.util.List;
 
/**
 * 文件與目錄工具：
 * - 遞歸遍歷目錄獲取文件列表
 * - 創(chuàng)建目錄
 */
public class FileUtils {
    /**
     * 遞歸查找目錄下所有文件。
     */
    public static List<Path> listFiles(Path dir) throws IOException {
        List<Path> list = new ArrayList<>();
        try (var stream = Files.walk(dir)) {
            stream.filter(Files::isRegularFile)
                  .forEach(list::add);
        }
        return list;
    }
 
    /**
     * 確保目標文件的父目錄存在。
     */
    public static void ensureParent(Path file) throws IOException {
        Path parent = file.getParent();
        if (parent != null && !Files.exists(parent)) {
            Files.createDirectories(parent);
        }
    }
}
 
// ===== 文件：src/main/java/com/encoding/BatchConverter.java =====
package com.encoding;
 
import java.io.IOException;
import java.nio.file.*;
import java.nio.charset.Charset;
import java.util.List;
import java.util.concurrent.*;
 
/**
 * 對目錄或列表文件進行批量編碼轉換。
 */
public class BatchConverter {
    private final ExecutorService pool;
    private final Config config;
 
    public BatchConverter(Config config) {
        this.config = config;
        this.pool = Executors.newFixedThreadPool(config.getThreadCount());
    }
 
    /**
     * 將 srcPath（文件或目錄）批量轉換到 destPath（文件或目錄）。
     */
    public void batchConvert(
            Path srcPath,
            Charset srcCharset,
            Path destPath,
            Charset destCharset) throws IOException, InterruptedException {
        if (Files.isRegularFile(srcPath)) {
            // 單文件
            pool.submit(() -> {
                convertFile(srcPath, destPath, srcCharset, destCharset);
            });
        } else {
            // 目錄：遞歸
            List<Path> files = FileUtils.listFiles(srcPath);
            for (Path f : files) {
                Path rel = srcPath.relativize(f);
                Path target = destPath.resolve(rel);
                pool.submit(() -> {
                    convertFile(f, target, srcCharset, destCharset);
                });
            }
        }
        pool.shutdown();
        pool.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS);
    }
 
    private void convertFile(
            Path inFile,
            Path outFile,
            Charset srcCharset,
            Charset destCharset) {
        try {
            FileUtils.ensureParent(outFile);
            try (var in = Files.newInputStream(inFile);
                 var out = Files.newOutputStream(outFile,
                     StandardOpenOption.CREATE,
                     StandardOpenOption.TRUNCATE_EXISTING)) {
                EncodingConverter.convert(
                    in, srcCharset, out, destCharset, config.getBufferSize());
            }
            System.out.println("轉換成功: " + inFile + " → " + outFile);
        } catch (IOException e) {
            System.err.println("轉換失敗: " + inFile + ": " + e.getMessage());
        }
    }
}
 
// ===== 文件：src/main/java/com/encoding/MainCli.java =====
package com.encoding;
 
import java.nio.charset.Charset;
import java.nio.file.Path;
import picocli.CommandLine;
import picocli.CommandLine.*;
 
/**
 * 命令行入口，使用 picocli 解析參數。
 */
@Command(name = "encode-convert", mixinStandardHelpOptions = true,
    description = "批量轉換文件或流的字符編碼")
public class MainCli implements Runnable {
 
    @Option(names = {"-sc", "--srcCharset"},
        description = "源字符集，默認 ${DEFAULT-VALUE}")
    private String srcCharset;
 
    @Option(names = {"-dc", "--destCharset"},
        description = "目標字符集，默認 ${DEFAULT-VALUE}")
    private String destCharset;
 
    @Option(names = {"-i", "--in"},
        description = "輸入文件或目錄，若省略則讀 stdin")
    private Path inPath;
 
    @Option(names = {"-o", "--out"},
        description = "輸出文件或目錄，若省略則寫 stdout")
    private Path outPath;
 
    private Config config = new Config();
 
    @Override
    public void run() {
        Charset sc = Charset.forName(
                srcCharset != null ? srcCharset : config.getDefaultSrcCharset());
        Charset dc = Charset.forName(
                destCharset != null ? destCharset : config.getDefaultDestCharset());
        try {
            BatchConverter bc = new BatchConverter(config);
            if (inPath == null || outPath == null) {
                // 流模式
                EncodingConverter.convert(
                    System.in, sc, System.out, dc, config.getBufferSize());
            } else {
                bc.batchConvert(inPath, sc, outPath, dc);
            }
        } catch (Exception e) {
            System.err.println("執(zhí)行失敗: " + e.getMessage());
        }
    }
 
    public static void main(String[] args) {
        int exitCode = new CommandLine(new MainCli()).execute(args);
        System.exit(exitCode);
    }
}
 
// ===== 文件：src/main/java/com/encoding/MainGui.java =====
package com.encoding;
 
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.nio.charset.Charset;
import java.nio.file.Path;
 
/**
 * Swing GUI 界面，后臺使用 SwingWorker 執(zhí)行轉換。
 */
public class MainGui extends JFrame {
    private JTextField srcField, destField;
    private JButton srcBtn, destBtn, startBtn;
    private JComboBox<String> srcCharsetBox, destCharsetBox;
    private JProgressBar progressBar;
    private JTextArea logArea;
    private Config config = new Config();
 
    public MainGui() {
        setTitle("字符編碼轉換工具");
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setLayout(new BorderLayout());
 
        // 上方：路徑和編碼選擇
        JPanel top = new JPanel(new GridLayout(3, 3, 5, 5));
        top.add(new JLabel("源文件/目錄:"));
        srcField = new JTextField();
        top.add(srcField);
        srcBtn = new JButton("選擇...");
        top.add(srcBtn);
 
        top.add(new JLabel("目標目錄:"));
        destField = new JTextField();
        top.add(destField);
        destBtn = new JButton("選擇...");
        top.add(destBtn);
 
        top.add(new JLabel("源編碼:"));
        srcCharsetBox = new JComboBox<>(
            new String[]{"UTF-8","GBK","ISO-8859-1"});
        srcCharsetBox.setSelectedItem(config.getDefaultSrcCharset());
        top.add(srcCharsetBox);
        top.add(new JLabel());
 
        top.add(new JLabel("目標編碼:"));
        destCharsetBox = new JComboBox<>(
            new String[]{"UTF-8","GBK","ISO-8859-1"});
        destCharsetBox.setSelectedItem(config.getDefaultDestCharset());
        top.add(destCharsetBox);
        startBtn = new JButton("開始轉換");
        top.add(startBtn);
 
        add(top, BorderLayout.NORTH);
 
        // 中部：日志與進度
        progressBar = new JProgressBar();
        add(progressBar, BorderLayout.SOUTH);
        logArea = new JTextArea(10, 80);
        logArea.setEditable(false);
        add(new JScrollPane(logArea), BorderLayout.CENTER);
 
        pack();
        setLocationRelativeTo(null);
        bindActions();
    }
 
    private void bindActions() {
        srcBtn.addActionListener(e -> {
            JFileChooser chooser = new JFileChooser();
            chooser.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);
            if (chooser.showOpenDialog(this)==JFileChooser.APPROVE_OPTION) {
                srcField.setText(
                    chooser.getSelectedFile().getAbsolutePath());
            }
        });
        destBtn.addActionListener(e -> {
            JFileChooser chooser = new JFileChooser();
            chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
            if (chooser.showOpenDialog(this)==JFileChooser.APPROVE_OPTION) {
                destField.setText(
                    chooser.getSelectedFile().getAbsolutePath());
            }
        });
        startBtn.addActionListener(e -> startConversion());
    }
 
    private void startConversion() {
        Path in = Path.of(srcField.getText());
        Path out = Path.of(destField.getText());
        Charset sc = Charset.forName((String)srcCharsetBox.getSelectedItem());
        Charset dc = Charset.forName((String)destCharsetBox.getSelectedItem());
        BatchConverter bc = new BatchConverter(config);
 
        // SwingWorker 執(zhí)行后臺任務
        SwingWorker<Void, String> worker = new SwingWorker<>() {
            @Override
            protected Void doInBackground() throws Exception {
                publish("開始轉換...");
                bc.batchConvert(in, sc, out, dc);
                return null;
            }
 
            @Override
            protected void process(java.util.List<String> chunks) {
                for (String msg : chunks) {
                    logArea.append(msg + "\n");
                }
            }
 
            @Override
            protected void done() {
                logArea.append("全部完成。\n");
            }
        };
        worker.execute();
    }
 
    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> new MainGui().setVisible(true));
    }
}
 
// ===== 文件：src/main/resources/application.properties =====
/*
app.srcCharset=UTF-8
app.destCharset=GBK
app.threadCount=4
app.bufferSize=8192
*/
 
// ===== 文件：src/main/resources/logback.xml =====
/*
<configuration>
  <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
    <file>app.log</file>
    <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
      <fileNamePattern>app.%d{yyyy-MM-dd}.log</fileNamePattern>
      <maxHistory>7</maxHistory>
    </rollingPolicy>
    <encoder>
      <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
    </encoder>
  </appender>
  <root level="INFO">
    <appender-ref ref="FILE"/>
  </root>
</configuration>
*/